1. Field of the Invention
The present invention relates to a drying apparatus for drying substrates including a semiconductor substrate, a glass substrate for a liquid crystal display device, a glass substrate for a photomask, a substrate for an optical disc, and the like after a processing solution (or a rinsing solution) such as deionized water is used to rinse the substrates and thereafter is spun off the substrates by rotational motion, and to a substrate processing apparatus including the drying apparatus.
2. Description of the Background Art
A substrate processing apparatus performs successive surface preparation processes including a chemical process using various liquid chemicals, a rinsing process using a rinsing solution such as deionized water, and the like. After the final rinse using deionized water, a drying process is performed as the final process. One of the substrate drying processes conventionally known in the art is a spin dry process for rotating a substrate at high speeds to spin off water from the surface of the substrate by centrifugal force in a single-wafer type substrate processing apparatus for processing substrates one by one.
For improvement in drying efficiency, a drying technique in which a vapor of material which reduces the surface tension of water adhering to a substrate is brought into contact with the substrate prior to the spin dry process is disclosed in Japanese Patent Application Laid-Open No. 05-243205 (1993) and Japanese Patent Application Laid-Open No. 2001-023946. Another drying technique in which an atmosphere in which a substrate is placed during the spin dry process is adjusted to a pressure lower than atmospheric pressure is disclosed in Japanese Patent Application Laid-Open No. 07-283126 (1995).
However, as patterns formed on a substrate become finer and more complicated, it is becoming difficult to reliably dry the substrate by removing water or moisture entering the inside of a microstructure, e.g. a space between lines of the patterns, the inside of a hole and the inside of a resist film, by the use of the disclosed drying techniques.